Combine vlookup and if functions in VBA

[Urner]

Here's what I've been trying to do for the last hour without any particular success:

I want to write a macro that will do exactly the same thing written below

IF result for vlookup(Range1,Range2,2,False) is blank THEN write down the word "COW" ELSE write the result of that vlookup.

Take into consideration that vlookup is not for a single cell but an entire column. Thus, I want to put "COW" only in the cells where vlookup returns no value (that is 0 or blank).


How I'm supposed to do it?

 

[CharlesChuckieCharles]

Try
=IF(ISNA(VLOOKUP($A11,L21:Q36,2,FALSE)),"COW",IF(VLOOKUP($A11,L21:Q36,2,FALSE)=0,"COW",IF(TRIM(VLOOKUP($A11,L21:Q36,2,FALSE))="","COW",VLOOKUP($A11,L21:Q36,2,FALSE))))

$A11 is the lookup value (you can't use a range here) but you can drag is down a column of values
$L$21:$Q$36 is the range to lookup where the corresponding Key to A11 is in L21 to L36 (the first column)

 

[Urner]

Thanks Chuckie, great answer. You are correct. However, the database I want this formula for is large and by saying large I mean that it is so big that pasting a formula for each cell will make the computer unresponsive for the entire day.

That's why I'd like to do it with macros to spare time and the computer.

Does anyone know how to do it?